UK could lose right to share security and business data with EU after Brexit, minister admits

James Brokenshire insisted the government remained “positive” that agreement would be reached, saying: “It is self-evidently in the interests of both side that the adequacy decision is in place by the end of the year.”

This is a classic "Prisoner's Dilemma" game: while it might be 'self evidently' best to reach one outcome, reaching that requires a level of trust in the other player that is simply not there and without it you end up in the situation where both players choose an inferior option.   Cummings is reportedly very keen on game theory: it is a pity some other Ministers and back-benchers seem completely unaware of it.